Monday 4 July 2011 15.06 EDT
First published on Monday 4 July 2011 15.06 EDT

An Olympic medal-winning boxer was among those injured by gunfire on Monday when government forces re-entered the city of Hama, which had slipped from the authorities' control for almost a month, according to activists.

The move could signal an escalating crackdown and draw increased international condemnation against the regime of Bashar al-Assad. The regime is simultaneously crushing protests while seeking to hold a "national dialogue" on Sunday to find a way out of the crisis.

Boxer Nasser al-Shami, 29, was among 40 people injured after security forces fired in the city, including a 13-year-old Omar Khalaf, according to activists in the local coordinating committees. One man was reported to be have been left disabled after being shot in the neck. At least 20 people including three women activists were detained.

"I want to leave because the situation is very bad," said a resident via Skype. Another man said he had evacuated his family from the city.

Hama, a Sunni city north of Damascus, with a population of 800,000 , had been celebrating its "liberation". The celebrations were due to the withdrawal of security forces and even traffic police, in the aftermath of huge funerals on 4 June, a day after security forces shot dead more than 70 protesters.

Since then thousands have taken nightly to the central Assi square calling for the fall of the regime and tearing down posters of the president.

But in a sign of a crackdown to come as protests continue, the regime apparently decided it could no longer tolerate the open dissent. Gunfire was reported in city suburbs on Sunday and in the early hours of Monday the army and security set up checkpoints on the outskirts of the city, activists said. Security forces entered, despite residents' efforts to keep them out with burning tires.

Residents also tried to protect the Hourani hospital, where the wounded were taken after forces raided neighbourhoods, according to activists. Damascus has been condemned by human rights groups for blocking access to medical treatment and arresting people in hospitals.

Al-Shami is in a stable condition, Rami Abdel-Rahman of the London-based Syrian Observatory for Human Rights told the Guardian. The boxer is one of the thousands injured since the uprising began in mid-March, in addition to more than 1,400 people who have been killed. One of a handful of high-profile Syrian sports personalities, Al-Shami won a bronze medal in the 2004 Olympic games in Athens in the heavyweight boxing category. Meanwhile, the army continued to assault villages including Haas and Kafer Nabul in the north-western province of Idleb on Monday, with reports of arrests, gunfire and snipers positioned on rooftops. It was unclear if anyone had been killed in the area as funerals for another two people shot dead in the Hajar al-Aswad neighbourhood of Damascus took place.

Despite government attempts to woo protesters with promises of reforms, Syrians have been braced for the regime to reassert control over Hama. Activists claimed that half a million took to the city's streets for the biggest protests yet last Friday. In an ominous sign, president Bashar al-Assad sacked governor Ahmad Khaled Abdel Aziz on Saturday, apparently for refusing to clamp down on protesters, activists said.

Hama is a sensitive city for Syrians and the regime after an assault on the city in 1982 killed at least 20,000 people. The assault was ordered by Bashar's father, Hafez al-Assad, to quash an armed Islamist uprising. The city was shelled from outside and some are believed to have starved to death during the siege, which went on for weeks without outside knowledge.